I realize there is a fine line between debuggers being used in software development and in RCE, but we shouldn't shy away from questions concerning dual-use tools just because they are dual-use.

As for the How does GDB's process recording work? question, I would say such things should also be considered on topic for the simple reason that reverse (code) engineering relies in large part on experience and circumstantial knowledge.

Therefore knowing how your tools work often provides missing jigsaw pieces should be considered an intrinsic part of the discipline.

Also:

Dynamic analysis just like static analysis is a part of RCE and debuggers play a vital role in it. Therefore knowing how certain features in a debugger work makes sense.

Even if the intention behind this question may not go that far, I think that most reverse engineers at one point or another have written their own debugger. Which goes to show how relevant it is to know how things work internally.